A binary ionic compound is known to contain a cation with 51 protons and 48 electrons. The anion contains one-third the number of protons as the cation. The num- ber of electrons in the anion is equal to the number of protons plus 1. What is the formula of this compound? What is the name of this compound?

The answer to your question is  Antimony chloride or Antimony trichloride

                                                      Formula   SbCl₃

Explanation:

Data

Cation                                   Anion

51 protons                             1/3 of the protons of the cation

48 electrons                          electrons = protons + 1

Process

1.- Look for the element that has an atomic number of 51

            Antimony = Sb

- It has 48 electrons, that means its charge is

            51 - 48 = 3

-Then, the formula of Antimony is

                                 Sb⁺³

2.- Divide 51 by 3

      51/3 = 17

-Look for the element with an atomic number of 17                  

-This element is Chlorine

                                Cl

-Calculate the charge of Chlorine

         17 - 18(17 + 1) = -1

-Then, the formula of chlorine is

                                 Cl⁻¹

3.- Write the formula of the compound

                               Sb⁺³ + Cl⁻¹  = SbCl₃

4.- Write the name of the compound.

This compound is a binary salt, so, it is called

                             Antimony chloride or Antimony trichloride